The present invention relates to a tape recorder, and more particularly to an apparatus for setting automatically the optimum performance characteristics for recording and reproduction in accordance with the magnetic property of magnetic tape to be used.
In the recent years, various magnetic tapes having excellent magnetic properties are commerically available. The magnetic tapes are selectively used according to the types of recording signals. To make full use of the performances of these mangetic tapes (.gamma.-ferric oxide, chromium-dioxide, ferrichrome, metal, and so on) they must be used in the optimum recording condition according to the types thereof and more strictly according to magnetic properties of the individual tapes even though they are of the same type. In order to satisfy such optimum recording condition, it is necessary to set the optimum performance characteristics such as the optimum recording level, the optimum recording bias level, the optimum recording equalization, and so on in recording circuits in accordance with the magnetic property of magnetic tapes.
In the conventional methods of setting the optimum performance characteristics generally a test signal is recorded on a magnetic tape while changing its recording level or recording bias level successively, and the recording level or bias level at which the reproduced signal level reaches a predetermined value or the maximum value is detected. The optimum performance characteristics are set according to the detected result. See, for example, Japanese patent preliminary publication Nos. Sho 55-17837 and 55-52510. In this kind of method, however, setting the optimum performance characteristics usually requires a long time of 20 to 40 seconds, and since the magnetic tape is running during this setting time the magnetic tape must be rewound after completing the setting in order to start the normal recording. In result, there has been occured the troublesomeness of manipulation of the tape recorder.